DOCSLIB.ORG

Bald Eagle & Endangered Species Haliaeetus Leucocephalus

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bald Eagle & Endangered Species Haliaeetus Leucocephalus Natural Heritage Bald Eagle & Endangered Species Haliaeetus leucocephalus Program State Status: Special Concern www.mass.gov/nhesp Federal Status: None Massachusetts Division of Fisheries & Wildlife DESCRIPTION: The Bald Eagle is one of the most impressive and majestic birds in North America. It is one of eight species in the genus Haliaeetus, the "fish" or "sea" eagles, and is the only member of the genus that occurs regularly in North America. This species is one member of the family of Accipiters, all of which are in the order Falconiformes. It is also the largest raptor (bird of prey) in Massachusetts, attaining a wingspan of 2.0 to 2.2 meters (6.5 to 7.0 feet) with a body length of 0.9 meters (3.0 feet), and a weight ranging from 3.6 to 6.6 kilograms (8 to 15 lbs.) at maturity. The sexes are similar in appearance but, as with most raptor species, the females are notably larger than the males. Photo by Bill Byrne, MassWildlife Adult Bald Eagles are distinctively colored with a white head and tail, brown body, pale yellow eyes, and bright yellow beak and feet. The adult plumage is attained at 4 eye and beak color also change with age, from dark to 5 years of age. The plumage of immature Bald Eagles brown and blackish-gray at hatching to bright yellow in adults. In all feathered stages, the tail is rounded and the may vary considerably. Immatures go through a sequence of plumage types before reaching maturity. lower half of the tarsus is unfeathered. These plumages include a uniformly dark phase in the first year, followed by phases with various amounts of Bald Eagles fly with heavy, deep strokes and soar on flattened wings. In silhouette, the beak, head, and neck white on the belly, back, underwings, tail, and head. The are almost as long as the tail. SIMILAR SPECIES IN MASSACHUSETTS: The large size and distinctive plumage of the Bald Eagle make it very easy to distinguish from all other birds in Massachusetts, with the exception of the Golden Eagle (Aquila chrysaetos). Both grow to approximately the same size, but the white head and tail of the adult Bald Eagle differentiates it from the Golden Eagle. Immature Bald Eagles may be confused with both immature and adult Golden Eagles. The adult Golden Eagle is nearly Cumulative Nesting Distribution in uniformly dark without the mottling found on the Massachusetts immature Bald Eagle. Golden Eagles at any age may 1990-2015 have relatively sharply defined, bright, clean white Based on records in patches of varying size at the base of the inner primaries Natural Heritage Database and outer secondaries on the wings and a clean white A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan Massachusetts Division of Fisheries & Wildlife 1 Rabbit Hill Rd., Westborough, MA; tel: 508-389-6300; fax: 508-389-7890; www.mass.gov/dfw Please allow the Natural Heritage & Endangered Species Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp Bald Eagle Fact Sheet – p. 2 area at the base of the tail. All immature Bald Eagles adequate supply of moderate-sized to large fish, an have whitish axillaries and, depending on age, can have unimpeded view, and reasonable freedom from human extensive, “dirty” white mottling virtually anywhere on disturbance. Wintering eagles require suitable roost trees the head, body, wing linings, and tail. The Golden for night roosting. Some such roosts may be 20 km or Eagle’s legs are feathered to its toes; the legs of the Bald more from feeding areas, occurring in favorable thermal Eagle are unfeathered. environments where roost trees are protected from the wind by topography or other trees. The use of these The Turkey Vulture is similar to an immature Bald protected sites helps minimize the energy stress Eagle in size and general coloration. At a distance, a encountered by wintering birds. The absence of a distinction can be made by looking at the birds as they suitable night roost could limit the use of otherwise soar. Turkey Vultures hold their wings somewhat suitable habitat. upright, forming a shallow "V" when soaring and rock from side to side as they ride thermal air currents. Bald LIFE CYCLE/BEHAVIOR: Courtship occurs in mid- Eagles hold their wings straight out from their body to late winter and is a spectacular sight consisting of while soaring, with only the tips of the primary feathers aerial loops, cartwheels, dives, and ending with the curved slightly upward. Eagles do not rock from side to prospective mating pair locking their talons together and side as they soar, but rather make broad, sweeping diving straight downward for hundreds of feet while circles as updrafts lift them skyward. At close range, the spinning head over heels. Bald Eagles may live up to 30 Turkey Vulture's small, featherless head (which is red in years, but mortality is relatively high in the immature adults and gray in juveniles) makes identification quite age classes. They mate for life, but if one member of a simple. pair dies or is killed, the other will actively court another mate. Sexual maturity is reached at four to six years of RANGE: Bald Eagles occur from Alaska and Canada age, but the birds may be considerably older before they south throughout the United States to Florida and Baja breed for the first time. California. In the lower 48 states, they occur sporadically over a wide area with notable seasonal The breeding season for Bald Eagles in Massachusetts concentrations in Florida, the Chesapeake Bay area, the begins with courtship during late fall or early winter. Mississippi Valley and Pacific Northwest. In After courtship, the mated pair builds a large nest during Massachusetts, occurrences are possible statewide, December–February. The nest is constructed with large especially during migration in March-April and sticks and lined with sprigs of pine, grasses, and other September-October; however, wanderers can appear soft materials. The male eagle collects the nest material virtually anywhere at any time. In Massachusetts, Bald and delivers it to his mate, who is responsible for most Eagles use the Quabbin Reservoir, the Connecticut of the actual nest construction. Once the nesting site is River, the Merrimack River, and the Assawompsett chosen, the mated pair will usually return every year to Pond complex throughout the year as both nesting and the same site and add to the existing structure. The nests wintering habitat. Bald Eagles also overwinter along the are located in hardwoods or conifers from 9 to 37 meters coast of Cape Cod, Buzzard's Bay and the islands of (30 to 120 feet) above the ground and may measure up Martha's Vineyard and Nantucket. Historically, the Bald to 3.6 meters (12 feet) high and 2.6 meters (8.5 feet) Eagle bred throughout most of North America prior to wide, with a weight of hundreds of pounds. Trees its widespread, well-publicized population decline selected for nesting (and sometimes for roosting and during the early to mid-1900s. However, during the past perching) tend to be relatively large and, preferably, several decades, the Bald Eagle has recolonized much of taller than their surroundings. Ideally, the nest lies below its historic range and continues to repopulate areas the top of the crown in a live tree, where the young are where suitable habitat still exists. sheltered from the elements but the parent birds are still afforded adequate aerial access (generally, from the HABITAT IN MASSACHUSETTS: Bald Eagles direction of the nearest water). usually inhabit coastal areas, estuaries, and larger inland waters. This species requires a great amount of shoreline The female Bald Eagle lays one to three (two average) habitat containing stands of forest for nesting and trees dull white eggs several days apart, usually during a projecting above the forest canopy for perching, an period between early March and early April. The eggs A Species of Greatest Conservation Need in the Massachusetts State Wildlife Action Plan Please allow the Natural Heritage & Endangered Species Program to continue to conserve the biodiversity of Massachusetts with a contribution for ‘endangered wildlife conservation’ on your state income tax form, as these donations comprise a significant portion of our operating budget. www.mass.gov/nhesp Bald Eagle Fact Sheet – p. 3 are incubated (mostly by the female) for approximately forest to development and agriculture), the Bald Eagle 35 days until hatching. The eggs do not hatch at the decreased in numbers in much of its range for many same time, giving the first hatchling a significant years. From 1917 to 1952, at least 128,000 Bald Eagles advantage over its siblings. Competition for food is were believed to have been killed in Alaska where there intense, and if the adult eagles are not able to provide was a bounty on the species. In the 20th century, the enough for all of their young, the older chick will take introduction of man-made chemicals and pollutants to advantage of its greater strength and size to seize most of the environment was implicated in death, increased the food provided by the parents, causing its younger susceptibility to death, and diminished reproductive siblings to starve. This behavior increases the probability success of Bald Eagles. DDT and its metabolites, as well that at least one chick will survive. Young eaglets grow as other organochlorines, are well-documented causes of rapidly and may eat up to two pounds of fish per day.
Load more

Recommended publications
  • Bald Eagle Haliaetus Leucocephalus
    Appendix A: Birds Bald Eagle Haliaetus leucocephalus Federal Listing N/A State Listing T Global Rank G4 State Rank S2 Regional Status Photo by Jason Lambert Justification (Reason for Concern in NH) Bald Eagle populations in the conterminous United States entered a severe population decline in the 1950s, largely a result of reproductive failure induced by biomagnification of the insecticide DDT (Buehler 2000). Some regional breeding populations, especially in eastern and southern states, became locally extirpated. This serious decline led to the designation of the bald eagle as Endangered under the Endangered Species Act. Following the banning of DDT and intensive reintroduction efforts, Bald Eagle populations gradually rebounded, and the species was removed from the federal endangered list in 2007. In the Northeast, recovery has been particularly strong since 2000. However, most states still consider Bald Eagle a SGCN due to historic extirpations and historic sensitivity to certain environmental stressors, particularly contaminants. Distribution Bald eagles currently occur and breed in all Lower 48 states and in Alaska. Based upon data provided by state agencies, from a population low of 417 breeding pairs in 1963 the U.S. Fish and Wildlife Service estimated that there were an estimated 1,500 breeding pairs in the contiguous 48 states in 1982 and an estimated 5,300 pairs in the same area in 1997 (derived from data in Buehler 2000), and nearly 9800 breeding pairs in the Lower 48 states in 2006. The USFWS estimated that there were 463 breeding pairs in the six New England states in 2006. The nationwide population has probably increased substantially since 2006, but more recently compiled information is not available from USFWS.
    [Show full text]
  • A Multi-Gene Phylogeny of Aquiline Eagles (Aves: Accipitriformes) Reveals Extensive Paraphyly at the Genus Level
    Available online at www.sciencedirect.com MOLECULAR SCIENCE•NCE /W\/Q^DIRI DIRECT® PHYLOGENETICS AND EVOLUTION ELSEVIER Molecular Phylogenetics and Evolution 35 (2005) 147-164 www.elsevier.com/locate/ympev A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level Andreas J. Helbig'^*, Annett Kocum'^, Ingrid Seibold^, Michael J. Braun^ '^ Institute of Zoology, University of Greifswald, Vogelwarte Hiddensee, D-18565 Kloster, Germany Department of Zoology, National Museum of Natural History, Smithsonian Institution, 4210 Silver Hill Rd., Suitland, MD 20746, USA Received 19 March 2004; revised 21 September 2004 Available online 24 December 2004 Abstract The phylogeny of the tribe Aquilini (eagles with fully feathered tarsi) was investigated using 4.2 kb of DNA sequence of one mito- chondrial (cyt b) and three nuclear loci (RAG-1 coding region, LDH intron 3, and adenylate-kinase intron 5). Phylogenetic signal was highly congruent and complementary between mtDNA and nuclear genes. In addition to single-nucleotide variation, shared deletions in nuclear introns supported one basal and two peripheral clades within the Aquilini. Monophyly of the Aquilini relative to other birds of prey was confirmed. However, all polytypic genera within the tribe, Spizaetus, Aquila, Hieraaetus, turned out to be non-monophyletic. Old World Spizaetus and Stephanoaetus together appear to be the sister group of the rest of the Aquilini. Spiza- stur melanoleucus and Oroaetus isidori axe nested among the New World Spizaetus species and should be merged with that genus. The Old World 'Spizaetus' species should be assigned to the genus Nisaetus (Hodgson, 1836). The sister species of the two spotted eagles (Aquila clanga and Aquila pomarina) is the African Long-crested Eagle (Lophaetus occipitalis).
    [Show full text]
  • Chromosome Painting in Three Species of Buteoninae: a Cytogenetic Signature Reinforces the Monophyly of South American Species
    Chromosome Painting in Three Species of Buteoninae: A Cytogenetic Signature Reinforces the Monophyly of South American Species Edivaldo Herculano C. de Oliveira1,2,3*, Marcella Mergulha˜o Tagliarini4, Michelly S. dos Santos5, Patricia C. M. O’Brien3, Malcolm A. Ferguson-Smith3 1 Laborato´rio de Cultura de Tecidos e Citogene´tica, SAMAM, Instituto Evandro Chagas, Ananindeua, PA, Brazil, 2 Faculdade de Cieˆncias Exatas e Naturais, ICEN, Universidade Federal do Para´, Bele´m, PA, Brazil, 3 Cambridge Resource Centre for Comparative Genomics, Cambridge, United Kingdom, 4 Programa de Po´s Graduac¸a˜oem Neurocieˆncias e Biologia Celular, ICB, Universidade Federal do Para´, Bele´m, PA, Brazil, 5 PIBIC – Universidade Federal do Para´, Bele´m, PA, Brazil Abstract Buteoninae (Falconiformes, Accipitridae) consist of the widely distributed genus Buteo, and several closely related species in a group called ‘‘sub-buteonine hawks’’, such as Buteogallus, Parabuteo, Asturina, Leucopternis and Busarellus, with unsolved phylogenetic relationships. Diploid number ranges between 2n = 66 and 2n = 68. Only one species, L. albicollis had its karyotype analyzed by molecular cytogenetics. The aim of this study was to present chromosomal analysis of three species of Buteoninae: Rupornis magnirostris, Asturina nitida and Buteogallus meridionallis using fluorescence in situ hybridization (FISH) experiments with telomeric and rDNA probes, as well as whole chromosome probes derived from Gallus gallus and Leucopternis albicollis. The three species analyzed herein showed similar karyotypes, with 2n = 68. Telomeric probes showed some interstitial telomeric sequences, which could be resulted by fusion processes occurred in the chromosomal evolution of the group, including the one found in the tassociation GGA1p/GGA6.
    [Show full text]
  • Field Identification of the Field Identification of the Field
    TOPICS IN IDENTIFICATION he Solitary Eagle ( Harpyhaliaetus solitarius ) is a large raptor that is closely related and similar in adult and immature plum- Tages to the black-hawks in the genus Buteogallus (Lerner and Mindell 2005). It is a rare and very local resident in a variety of wet and dry forested hills and highlands from northern Argentina to northern Mexico (del Hoyo et al. 1994, Ferguson-Lees and Christie 2001). The species has been collected in Mexico not far from the Texas border (see Discussion, pp. 72 –73), so it is possible that it has occurred in the ABA Area. The handful of specimens and nest records of this eagle are from 700 to 2,000 meters above sea level (Brown and Amadon 1968). FFiieelldd IIddeennttiifificcaattiioonn ooff tthhee SSOOLLIITTTAAARRRYYY EEAAAGGGLLLEEE Nevertheless, sightings of this eagle are occasionally reported from lowland tropical rain forest, e.g., at Tikal, Guatemala (Beaver et al. 1991) and the Tuxtlas Mountains of south - William S. Clark ern Veracruz, Mexico (Winker et al. 1992). The species has been reported on some pro - 2301 South Whitehouse Circle fessional bird tours at such lowland sites as Palenque and the Usumicinta River in south - Harlingen, Texas 78550 ern Mexico. All of these accounts have relied on large size and gray coloration as the [email protected] field marks to distinguish the eagles from the much more abundant Common Black- Hawk ( Buteogallus anthracinus ) and Great Black-Hawk ( B. urubitinga ). H. Lee Jones Howell and Webb (1995) were skeptical and stated that most lowland records of the 4810 Park Newport, No.
    [Show full text]
  • Bald Eagle Haliaeetus Leucocephalus
    Wyoming Species Account Bald Eagle Haliaeetus leucocephalus REGULATORY STATUS USFWS: Delisted; Migratory Bird USFS R2: Sensitive USFS R4: Sensitive Wyoming BLM: Sensitive State of Wyoming: Protected Bird CONSERVATION RANKS USFWS: Bird of Conservation Concern WGFD: NSS3 (Bb), Tier II WYNDD: G5, S4B/S5N Wyoming Contribution: LOW IUCN: Least Concern PIF Continental Concern Score: 9 STATUS AND RANK COMMENTS Bald Eagle (Haliaeetus leucocephalus) is provided international protection under the Federal Migratory Bird Treaty Act of 1918, as amended 1. In 1940, Bald Eagle was provided protection under the Bald and Golden Eagle Protection Act 2. In 1966, the southern subspecies was listed as federally endangered under the Endangered Species Preservation Act; the entire population in the contiguous United States was listed as endangered in 1978 under the 1973 Endangered Species Act (ESA). A significant increase in numbers of nesting pairs, productivity, and distribution allowed Bald Eagle to be reclassified from Endangered to Threatened in 1995 under the ESA 3. Bald Eagle was delisted in 2007, and numbers are considered to be stable to increasing across its range 4. The species has been assigned different state conservation ranks by the Wyoming Natural Diversity Database for the breeding season and nonbreeding season because the abundance of the species is different between seasons. NATURAL HISTORY Taxonomy: Bald Eagle is a member of the family Accipitridae, which includes kites, eagles, harriers, and hawks 5. There are two subspecies of Bald Eagle; H. l. alascanus is found north of 40 degrees latitude across North America, including Wyoming, while H. l. leucocephalus is found south of 40 degrees latitude in the Gulf coast states 6.
    [Show full text]
  • Regional Specialties Western
    REGIONAL SPECIALTIES WESTERN OSPREY 21 - 26” length SOUTHERN . FERRUGINOUS . Eagle sized; clean, white body. HAWK Black wrist marks. 20 - 26” length . Glides with kink (M) in long, narrow wings. MISSISSIPPI . Largest buteo; eagle-like. KITE . Pale below with dark leggings. 13 - 15” length . Mostly white tail; 3 color morphs. Long, pointed wings; slim body. Light body; dark wings; narrow, black tail. Not to scale. Buoyant, acrobatic flight. NORTHERN HARRIER 16 - 20” length PRAIRIE FALCON 14 - 18” length . Long, narrow wings and tail; sharp dihedral. Size of Peregrine; much paler plumage. Brown above, streaked brown below – female. Narrow moustache; spotted breast; long tail. Gray above, pale below with black wing tips – male. Dark armpits and partial wing linings. WING PROFILE IMMATURE BALD EAGLE BALD EAGLE GOLDEN EAGLE . Immature birds vary GOLDEN EAGLE greatly in the amount 27 to 35” length of white spotting on body and wings. White showing on wing linings is surely a Bald Eagle. BALD EAGLE . Like large buteo, curvy wings. Head protrudes much less than tail. Slight dihedral to wing profile. NOTE: Some hawks soar and glide with their wings raised above the horizontal, called a dihedral. 27 to 35” length . Head and tail length similar. Long, flat wings. Straight leading edge to wings. 24 to 28” length This guide developed by Paul Carrier is the property of the Hawk Migration Association of North America (HMANA). HMANA is TURKey VUltUre a membership-based, non-profit organization committed to the . Dark wing linings with light flight feathers. conservation of raptors through the scientific study, enjoyment, and . Small head; long tail; sharp dihedral.
    [Show full text]
  • An Early Pleistocene Eagle from Nebraska
    248 SHORT COMMUNICATIONS kunthii blossoms by Bombus queens occurred and depend on many factors. That hummingbirds and the workers were unable to secure nectar while positioned ancestor of P. kunthii co-existed may be assumed; within the floral tube, probably as much as lo-20 otherwise its adaptation to hummingbird pollination per cent more nectar was available to Bombus p&her would make little sense. Thus it is possible that P. and Bombus trinominatus populations during this kunthii could have undergone much of its development period due to the feeding activity of Diglossa. under selective pressure from hummingbirds; still, it is clear that Diglossa baritula has co-existed with DISCUSSION AND CONCLUSIONS hummingbirds throughout New World montane hab- Grant and Grant (1968) have proposed an explanation itats for some time and therefore an earlier and more for the reciprocal evolution of hummingbirds and the important role in the evolution of P. kunthii would plants upon which they feed. According to this inter- not be unexpected. This is not to suggest that exploita- pretation most hummingbird-pollinated flowers, espe- tion late in the evolutionary development of P. kunthii cially temperate species, have evolved from bee flowers would be insignificant. Even at present, given the (Grant 1961; Grant and Grant 1965). The process potential counter-selection pressures on P. kunthii involves an incipient stage during which a primitive from bees, the presence of Dglossa perforations un- hummingbird or progenitor already “preadapted” to doubtedly precludes a certain amount of bee pollina- feed on a particular bee flower (in the sense of tion which would probably otherwise occur, helping securing insects within the corolla, or nectar, or both), to maintain the selection pressures on P.
    [Show full text]
  • Predation by a Golden Eagle on a Brown Bear Cub
    SHORT COMMUNICATION N Sørensen et al. Predation by a golden eagle on a brown bear cub Ole J. Sørensen1,4, Mogens Totsa˚ s2, Tore eagles attending bears. Murie hypothesized that Solstad2, and Robin Rigg3 eagles attending bears were waiting for opportunities to capture prey trying to escape from the bears. He 1North-Trondelag University College, Department of also observed eagles swooping at and diving low over Natural Resource Sciences and Information Technology, grizzlies and other carnivores, but interpreted this Box 2501, N-7729 Steinkjer, Norway behavior as play or curiosity, rather than predation. 2 Norwegian Nature Inspectorate, N-7485 Trondheim, C. McIntyre (US National Park Service, Fair- Norway 3 banks, Alaska, USA, personal communication, 2008), Slovak Wildlife Society, PO Box 72, 033 01 Liptovsky a golden eagle researcher in Denali National Park for Hradok, Slovakia many years, has never seen an eagle attack a bear, although she has often observed eagles following Abstract: During spring 2004 an adult female brown bears in open terrain, perhaps positioning themselves bear (Ursus arctos) and her 3 cubs-of-the-year were to take prey escaping from the bear as suggested by observed outside their den on a south-facing low- Murie. Commensalistic hunting, as well as curious or alpine slope in central Norway. They remained near play behavior by eagles in the vicinity of bears, could the den for 8–10 days and were, except for one day, be misinterpreted as eagles hunting, attacking, or observed daily by Totsa˚s and other wardens of the inspecting bears as possible prey. Predation by eagles Norwegian Nature Inspectorate.
    [Show full text]
  • Anthony, R.G., J.A. Estes, M. A. Ricca, A. K. Miles, and E. D. Forsman
    Ecology, 89(10), 2008, pp. 2725–2735 Ó 2008 by the Ecological Society of America BALD EAGLES AND SEA OTTERS IN THE ALEUTIAN ARCHIPELAGO: INDIRECT EFFECTS OF TROPHIC CASCADES 1,5 2 3 3 4 ROBERT G. ANTHONY, JAMES A. ESTES, MARK A. RICCA, A. KEITH MILES, AND ERIC D. FORSMAN 1U.S. Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon 97331 USA 2U.S. Geological Survey, Western Ecological Science Center, University of California, Santa Cruz, California 95060 USA 3U.S. Geological Survey, Western Ecological Science Center, University of California, Davis, California 95616 USA 4U.S. Forest Service, Pacific Northwest Research Station, 3200 Jefferson Way, Corvallis, Oregon 97331 USA Abstract. Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence of sea otters on the ecology of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Islands, Alaska, USA. We studied the diets, productivity, and density of breeding Bald Eagles on four islands during 1993–1994 and 2000–2002, when sea otters were abundant and scarce, respectively. Bald Eagles depend on nearshore marine communities for most of their prey in this ecosystem, so we predicted that the recent decline in otter populations would have an indirect negative effect on diets and demography of Bald Eagles. Contrary to our predictions, we found no effects on density of breeding pairs on four islands from 1993–1994 to 2000–2002. In contrast, diets and diet diversity of Bald Eagles changed considerably between the two time periods, likely reflecting a change in prey availability resulting from the increase and subsequent decline in sea otter populations.
    [Show full text]
  • Bald Eagle Nest in a Manitoba Heron 30L0ny Eagle/Coyote
    The Ring-billed Gull colony were several weeks old while heron appeared to contain complete chicks were just beginning to hatch. dutches, although no young had yet The observation is of interest and latched. Their nests contain “usually worthy of future field observation to three, sometimes two, very rarely determine if the two species will co¬ four” eggs.1 Sixty-two of these Ring- exist in such close proximity. The pilled Gull nests contained four eggs, abandonment of a heron colony at eight had five eggs and one had six Beaver Lake (54° 43’ N, 111° 53’ W) aggs. The remaining gull nests had between 1970 and 1972 supposedly he usual three. Numbers of four- due to the establishment of an eagle and five-egg clutches appear nest in the colony was reported by significant because they infer a larger Vermeer (Can. Field Nat. 87:427- than normal clutch size rather than 432). the pairing of two females. Other Ring-billed Gull colonies surveyed in 1979 contained abnor¬ mal clutch sizes, but none ap¬ EAGLE/COYOTE proached the proportion INCIDENT documented on the Bachelor’s Island polony. SIG JORDHEIM, White Bear, Sask¬ HARRISON, COLIN. 1978. A field guide atchewan, SOL 3L0. to the nests, eggs and nestlings of North American birds. Collins, New On 25 November 1979, I was on a York. 416 pp. hill overlooking Lake Diefenbaker. At this late date there were still several hundred Canada Geese and Mallard ducks on about an acre of open BALD EAGLE NEST IN A water toward the south shore of the MANITOBA HERON lake.
    [Show full text]
  • Helpful Hawks Silhouettes That Save
    HH- 1 Helpful Hawks Topic Silhouettes that save Page ird feeders provide excellent opportunities fall unnoticed in shrubbery of be scavenged Bto watch our favorite birds “up close and by cats, crows and squirrels. In addition to personal.” Unfortunately, they also pose the dead bodies, there are other tell-tale marks risk of substantially increasing avian mortality. that can help you determine if your windows are killing birds such as a bit of blood or Increased risks to birds at bird feeders come feathers stuck on the pane. Another tell-tale in three forms, (1) natural and unnatural sign is a “bird angel”--the impression left on predation, (2) contagious diseases, and (3) the window by the birds feathers. Some bird window strikes. angels are so clear that they can be used to tell which species collided with the window. This activity is designed to help you reduce the risk of window strikes. Suggestions for Reducing window strikes reducing predation and contagious diseases at your feeders are provided at the end of One easy way to reduce window strikes near the activity. bird feeders is to place your feeders within a foot or two of your windows, or, alternatively, Window strikes pose a significant hazard to more than 20 feet from your windows. birds (see Facts about window strikes, Placing feeders close to windows reduces below). Your window may be killing birds even the risk of window strikes by reducing the if you don’t find any bird bodies, which can Facts about window strikes Gender, age, and whether the bird is a migrant or resident, appear to have little effect on a bird’s 25%, or 225 of 917 of all bird vulnerability to window strikes.
    [Show full text]
  • Raptor Identification
    Raptor Identification JCOS Raptor Protection Number of volunteers: 32 Total volunteer observation hours: 708 Number of nests monitored in 2018: 56 Species monitored include: Golden eagle, prairie falcon, peregrine falcon, great horned owl, Swainson’s hawk, red-tailed hawk, cooper’s hawk What is a raptor? Usually people answer this question with: A bird that eats other animals. What is a raptor? And here is another common answer… What is a raptor? Some birds look a lot like raptors, but are not. What is a raptor? Some birds act a lot like raptors, but are not. Audubon Guide to North American Birds What is a raptor? A raptor is a diurnal bird that eats other animals using specialized tools. What is a raptor? Raptors are a “gateway” species. Easy to see Engaging to watch Offer insight into the health of an ecosystem Nature Hates Competition: Habitat? Behavior? Flight pattern? Wing pattern? Raptor ID challenges: Color morphs Juvenile vs. adult plumage Sexual dimorphism Perching raptors offer scant ID info compared to raptors in flight Main Raptor Groups: Eagles Accipiters Buteos Falcons Raptors: Eagles Raptors: Eagles White head Bald Eagle Massive, yellow bill White tail Yellow talons Raptors: Eagles No white head Massive bill (but Juvenile Bald Eagle not yellow) White feathers scattered through the breast and wings Yellow talons Raptors: Eagles Golden Eagle Golden head Massive bill Some white in tail and wings in juvenile. Raptors: Accipiters https://www.youtube.com/watch?v=Td8bmr-6AHs https://www.youtube.com/watch?v=2CFckjfP-1E Dark gray
    [Show full text]